As is known in the automotive industry, there are at present acoustic devices located in the inner part of a vehicle engine's air filter (10), which can be, for example, the known sound-reducers or truncated-cone sound reducers, made of plastic or metal, which are generally coupled in circular apertures (1-A1, 2-A1 as shown in FIG. 1 herein) made respectively in one side of the upper compartment (1) and the lower compartment (2) of the air filter (10). The air filter element (3) remains pressed between the two compartments (1, 2) and the internal supports for the air filter element (3), as can be seen on FIG. 1 annexed hereto, which shows a lateral cross-section of an inlet assembly, showing the conventional air filter.
There are also conventional acoustical devices located in the outer part of the air filter (10), which can be for example, tubes or boxes that control the air input to the engine and which are arranged upstream of the air filter (10), coupled to the nozzle (1-A) of the dirty air inlet of the upper compartment (1) of air filter (10).
The above mentioned conventional acoustic devices have the scope of reducing the inlet noises. It can be seen, however, that the conventional clean air passage tube (5) made of rubber or plastic, which is coupled to the clean air exit nozzle (2-A) of the lower compartment (2) of air filter (10) and to the carburetor nozzle (6) is merely a leak proof tube (5) that ensures a perfect seal for the conducted air. However, the fact that the tube (5) is made of rubber or plastic causes it to transmit the engine noise, an aspect that is evidence of a technological short coming. Since the clean air passage tube (5) interconnects the air filter (10) and the carburetor (6), it is an integral part of the vehicle engine inlet assembly.